Furnace structures



Jan. 21 1955 o. M. 'FOX 2,820,439

FURNACE ST'RUCTURES 2 Sheets-Sheet 1 Filed Dec. 25, 1949 INVENTOR OSCAR M. Fox

Jan. 21, 1958 I I o. M. Fox

- FURNACE'STRUCTURES Filed nechzz, 1949 2 Sheets-Sheet 2' INVENTOR OSCAR M. Fox

United States Patent FURNACE STRUCTURES Oscar M. Fox, Pittsburgh, Pa., assignor, by mesne assignments, to Blaw-Knox Company, Pittsburgh, Pa., a corporation of Delaware Application December 23, 1949, Serial No. 134,692

15 Claims. (Cl. 122-499) This invention relates to furnace structures, and in particular to furnace doorframes and fasteners such as are used on industrial furnaces.

- Furnace doorframes such as, for example, water-cooled doorframes used on open hearth furnace structures must be removed from time to time and replaced as they need repairs or become worn. It is often necessary to replace such frames during the life of the furnace. Since it is uneconomical to shut down the furnace for such an operation it becomes necessary to replace the frame while the furnace is at or near operating temperature. At such times the intense heat surrounding the furnace opening makes working conditions exceedingly hazardous and diflicult and the job of replacing the frames is consequently expensive and time-consuming.

Furnace frames such as are presently used are ordinarily fastened to the furnace framework by being bolted in position after first being raised into proper registry with the arch of the furnace by the use of pinch bars and wedges.

I have discovered a novel means for fastening furnace doorframes in place which avoids the many difficulties of prior art practices. By the use of my invention a furnace doorframe may be installed while the furnace is in operation without endangering the workmen and without the diificulties attendant in bolting the doorframe to the framing of the furnace.

In general, my invention comprises, in combination, a furnace doorframe having supporting means extending from the top thereof, bearing means on a framing member of the furnace above the furnace opening, which bearing means have at least one inclined surface, and an incline engaging means between the supporting means and the inclined surface of the bearing means to hold them in fixed relation to one another. tion of the furnace doorframe and fastening means of my invention will be more clearly understood, however, by referring to the accompanying drawings, in which Figure l is a section through a furnace opening showing a doorframe and fastener of my invention being placed in a furnace opening;

Figure 2 is a section through a furnace opening showing a doorframe and the fastener of my invention in position in the furnace opening before the cam surface is engaged;

Figure 3 is a partial end elevation of a doorframe and fastener according to my invention;

Figure 4 is a section on the line IVIV of Figure 3;

Figure 5 is an end elevation showing the fastening means of Figure 3 in multiple arrangement;

Figure 6 is a top plan view of another embodiment of my invention;

Figure 7 is a section on the line VII-VII of Figure 6;

Figure 8 is a top plan view of a further embodiment of my invention;

Figure 9 is a section on the line IXIX of Figure 8; and

The structure and opera- I Figure 10 is a top plan view of another embodiment of my invention.

Referring first to Figure 1, I have illustrated a watercooled doorframe 10 and integral skewback channel cooler 11 being inserted in an opening 12 in a furnace (only partially shown), the opening being provided with a framing member including a skewback portion. The doorframe lt) is swung into position before the furnace opening with the legs 13 of the doorframe resting on the breastplate l4 behind the foreplate 15. The upper end of the frame is next moved into contact with the skewback 16 of the furnace, as shown in Figure 2. The frame as it rests on the breastplate 14 is separated from the skewback by the distance X which is the distance from the junction of the skewback cooler and the frame and an arc Y formed by the inner end of the skewback cooler rotating about the point of contact of the legs 13 on the breastplate 14 of the furnace.

In Figures 3 and 4, I have illustrated a doorframe and the fastening means, shown in Figures 1 and 2 in more detail. A supporting arm 17 is fastened to the top of the doorframe 10 so as to be offset from the plane of the doorframe and to extend over the skewback channel 16 of the furnace. A rotating cam 18 is pivotally mounted on a shaft 19 passing through the offset ends of the supporting arms 17. The cam 18 is proportioned with its center of gravity so located that when moved past dead center it will fall against the inclined upper surface 20 of bearing member 21 welded to a furnace framing member, in this case the top of the sltewback channel 16. The angle of the inclined surface 26 of bearing member 21, the radius and pitch of the cam 18 and the relative location of the cam pivot are so chosen that the structure is self-locking and is stable under the weight'of the frame thus eliminating the need for wedges under the legs of the frame and the necessity of bolting the frame to the furnace framework. An enlarged portion 22 may be provided on the end of the cam 18 to increase the mass of the cam so as to cause it to rotate into engaging position more positively.

In one form of cam the cam means has an effective contour following the formula R0 Cos N where R is the radius after N increments, R0 is the base or starting radius, N is the number of increments and 0 is the degrees of each increment.

In installing a door frame having the fastener of Figures 1 through 4 the cam 18 is rotated to the position of greatest clearance (see Figures 1 and 2) at which point the stop pin 23 engages the end of the recess 24 forming the upper hook of the cam. In other words the cam is rotated as far as it will go in the clockwise direction viewing Figure 4. With the cam in this position the frame is placed on the breastplate 14 of the furnace and moved into position against the skewback 16. The cam 18 is then moved in the counterclockwise direction past dead center whereupon it falls into contact with the inclined surface 20 of bearing member 21. As the frame is subsequently lifted into position in the furnace opening the cam 18 swings further in the counterclockwise direction maintaining engagement with the inclined surface 20 of the bearing member 21 and thus latches and supports the frame in any position to which it may be lifted.

The cams 18 may be grouped in multiple arrangement at shown in Figure 5 in which case each separate cam making up the group of multiple cams has a different contour than any other cam in the group so that if the frame is lifted beyond the supporting position of the smallest cam then the next largest cam will become effective, etc.

Prior to my invention the conventional practice for installing doorframes was to rest the frame on the breastplate 14 of the furnace in the furnace opening 12. The frame. 10. as then raised, in position by pinch bars and fastened either by driving wedges beneath the legs 13 of the frame, or by bolting the doorframe to the furnace framework. In either case the installation was hot and dangerous,

In the embodiment shown in Figures 6 and 7 l have shown a pair of supporting arms 34 attached to the top of the doorframe 10. Each of these arms is offset from the plane of the doorframe so as to extend over the skewback 16. of the furnace. Each arm has :1 lug 36 extending from its offset end. A bearing member 37 having an, inclined surface 38 is welded to the top 39 of the skewbaclc 16 of the furnace. A roller as is placed between the lugs 36 and inclined surface 37 of the bearing member to hold the bearing member 37 and lug in fixed relative position.

In inst-allating a door according to this embodiment the roller 40 is mounted on the lugs 36 and held in posidon thereon by spring clips 41. The frame 1t is first moved into position on the breastplate and then into position against the skewback 16. As the frame moves in against the skewbaclc the inclined bearing member 37 passes between the lugs 36 and below the roller 40 which is held in position on the lugs by the spring clips 41 as shown in dotted lines in Fig. 7. The roller 49 is pulled from the spring clips 41 into position between the lugs 36 and bearing member 37. When the doorframe is raised into position within the opening of the furnace the roller 40 drops between the bearing member 37 and the lugs 36 wedging the doorframe in position.

In the embodiment illustrated in Figures 8 and 9, I have shown a supporting arm 4-2 pivoted on a shaft 43 between two lugs 44 welded to the top of the doorframe 10. A bearing member 45 is welded to the top of the skewback channel 16 of the furnace so as to extend over the edge of the skewback above the doorfrarne. The bearing member 45 is provided with a bottom opening 46, a rear inclined face 47 and a pair of inclined bearing lugs 48. The bottom opening 46 is adapted to receive the supporting member 42 which is pivoted through the opening 48:: between the bearing lugs 48 and to hold it in locked position by the wedging action or rolls 49 one of which engages the inclined face 4'7 and one side of the supporting member 42, while the other engages the two inclined bearing lugs :8 and the opposite side of the supporting member.

In Figure 10 I have shown still another embodiment in which the rolls 4-9 of Figures 8 and 9 are replaced by incline engaging blocks of trapezoidal section.

In order to release a frame secured by any of the above described fasteners it is only necessary to raise the frame sufficiently to take the load off the fastener which then releases the locking element which may be raised out of engagement with the bearing member and the supporting member. The frame may then be removed and another frame inserted in its place in the manner above described.

While the combination of my invention finds its greatest usefulness in archless frames, since the furnace structure tends to distort during use requiring that the doorframe be more critically fitted to the opening in the furnace in order to protect the skewback channel, it may be used in conjunction with frames which do not include the water-cooled ledge. Such frames are used, for example, with furnaces which incorporate a brick arch to protect the skewback instead of the water-cooled ledge illustrated in the drawings.

It is obvious that one or more combinations of supporting members, bearing members and incline engaging means may be mounted on a furnace door and frame depending upon the size, shape and weight of the door.

Although I have illustrated several preferred embodi- 4 ments of my invention it will be understood that it may be otherwise embodied within the scope of the following claims.

I claim:

1. In combination, a furnace with an opening, a framing member above said opening, a furnace doorframe, suspending means extending vertically from the top of said doorfrarne, bearing means on the framing member of the furnace above the furnace opening, said bearing means having at least one inclined surface, and inclined engaging means between the suspending means and the inclined surface of the bearing means and movable with respect to the suspending means by gravity independently of the suspending means adjustably suspending the doorfrarne vertically positioned in the furnace opening.

2. In combination, a furnace with an opening, a framing member above said opening, a furnace doorframe, two suspending members extending vertically from the top of said doorframe, bearing mean on the framing member of the furnace above the furnace opening, said bearing means equal in number to the number of suspending members and having at least one inclined surface, and inclined engaging means between each of the suspending members and the inclined surface of the bearing means and rotatable with respect to the suspending means by gravity independently of the suspending means adjustably holding the doorframe vertically positioned in the furnace opening.

3. In combination, a furnace with an opening, a framin member above said opening, a furnace doorframe, suspending means extending vertically from the top of said doorframe, bearing means on the framing member of the furnace above the furnace opening, said bearing deans having at least one inclined surface and rotatable cooperating means between the suspending means and the inclined surface of the bearing means adjustably holding the doorframe vertically positioned in the furnace opening, said rotatable cooperating means rotating by gravity independently of the suspending means.

4. In combination, a furnace with an opening, a framing member above said opening, a furnace doorframe, at least two suspending members extending vertically from the top of said doorframe, bearing means on the framing member of the furnace above th furnace opening, said bearing means equal in number to the number of suspending members and having at least one inclined surface, and rotatable cooperating means between each of the suspending members and the inclined surface of the bearing means holding the doo-rframe adjustably vertically positioned in the furnace opening, said rotatable cooperating means rotating by gravity independently of the suspending means.

5. In combination, a furnace with an opening, a framing member above said opening, a water-cooled furnace doorframe, at least two suspending members extending from the top of said doorframe, said suspending members being offset from the plane of the doorframe to extend over the framing member of the furnace, rotatable cam means on said suspending members, and inclined bearing means fastened to the framing member to supportably engage the cam means.

6. In combination, a furnace with an opening, a framing member above said opening, a water-cooled furnace doorframe, suspending means extending from the top of said doorframe, said suspending means having an offset portion adapted to extend over the framing member of the furnace, rotatable cam means on said offset portion, and inclined bearing means fastened to the framing member to supportably engage the cam means.

7. In combination, a furnace with an opening, a framing member above said opening, a water-cooled furnace doorframe, suspending means extending from the top of said doorfrarne, said suspending means having an offset portion adapted to extend over the framing member of the furnace, rotatable cam means on said suspending means, weighting means eccentrically on said cam means tending to rotate the cam means, and inclined bearing means fastened to the framing member to supportably engage the cam means.

8. In a combination such as claimed in claim 7 in which the cam means has an effective contour following the formula where R is the radius after N increments, R0 is the base or starting radius, N is the number of increments and 0 is the degrees of each increment.

9. In combination, a furnace with an opening, a framing member above said opening, a water-cooled furnace doorframe, at least two suspending members extending from the top of said door frame, said suspending members having an offset portion adapted to extend over the framing member of the furnace, a plurality of cams each of different contour pivoted on the offset portion of each suspending member, and inclined bearing means fastened to the framing member to supportably engage at least one of the cams.

10. In a combination such as claimed in claim 9 in which each of the cams carries weighting means eccentrically mounted thereon with respect to the pivotal point of the cam.

11. In combination, a furnace with an opening, a framing member above said opening, a furnace doorframe, suspending means extending from the top of said doorframe, said suspending member being offset from the plane of the doorframe to extend over the framing member of the furnace, inclined bearing means on the framing member, and roller means between the suspending means and the bearing means to hold the doorframe adjustably positioned in the furnace opening, said roller means rotating independently of the suspending means.

12. In combination, a furnace with an opening, a framing member above said opening, a furnace doorframe, at least two suspending members extending from the top of said doorframe, said suspending members having an oifset portion adapted to extend over the framing member of the furnace when the doorframe is in position, locking lugs on said suspending members, inclined bearing members on the framing member corresponding in number to the number of suspending members, and locking rollers equal in number to the number of suspending members and bearing members between said members to hold the doorframe adjustably positioned in the furnace opening, said rollers rotating independently of the suspending means.

13. In combination, a furnace with an opening, a framing member above said opening, a furnace doorframe, at least two suspending members pivotally attached to the top of said doorframe, bearing members equal in number to said suspending members mounted on the framing member of the furnace above a furnace opening, each of said bearing members having an aperture therein adapted to receive a suspending member, said aperture having opposed inclined faces, and incline engaging means between each suspending member and the inclined faces of the corresponding bearing member, said inclined engaging means moving independently of the suspending means.

14. In combination, a furnace with an opening, a framing member above said opening, a furnace doorframe, at least two suspending members pivotally attached to the top of said doorframe, bearing members equal in number to said suspending members mounted on the framing member of the furnace above a furnace opening, each of said bearing members having an aperture therein adapted to receive a suspending member, said aperture having opposed inclined faces, and rollers between each suspending member and each inclined face of the corresponding bearing member, said rolls moving independently of the suspending member.

15. In combination, a furnace with an opening having a skewback portion, a framing member above said opening, a Water-cooled furnace doorframe having an inwardly extending skewback cooler fitting into the skewback portion of the opening, at least two suspending members extending from the top of said doorframe, said suspending members having an offset portion extending over said framing member above the opening, bearing means on said framing member above the furnace opening, said bearing means having at least one inclined surface, and incline engaging means between the suspending means and the inclined surface of the bearing means and movable with respect thereto by gravity independently of the suspending member to hold the doorframe adjustably positioned in the furnace opening with the skewback; cooler against the skewback portion of the furnace opening.

References Cited in the file of this patent UNITED STATES PATENTS 238,411 Lowell Mar. 1, 1881 727,950 Hook May 12, 1903 864,752 Knox Aug. 27, 1907 897,623 Howland Sept. 1, 1908 1,022,757 Sammel Apr. 9, 1912 1,168,649 Knox Jan. 18, 1916 1,191,103 Edwards July 11, 1916 1,439,859 Ballard Dec. 26, 1922 1,541,016 Wertheim et al June 9, 1925 1,588,707 Csiga June 15, 1926 1,611,819 Davison Dec. 21, 1926 1,659,317 Farley Feb. 14, 1928 1,819,467 Jones Aug. 18, 1931 2,038,462 Wellman Apr. 21, 1936 2,091,442 Heiman Aug. 31, 1937 2,132,507 Baker Oct. 11, 1938 FOREIGN PATENTS 546,609 Germany Mar. 16, 1932 44,199 France Aug. 20, 1934 (Addition to No. 753,369)

18,143 Great Britain Aug. 13, 1906 28,626 Great Britain Dec. 27, 1902 110,452 Great Britain Oct. 25, 1917 171,675 Great Britain Apr. 27, 1922 362,228 Great Britain Dec. 3, 1931 519,118 Great Britain Mar. 18, 1940 U. 5. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION Patent Non 820,439 January 21, 1958 Oscar Ma Fox It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 4, for "as then" read was then column 4, lines ll and 24, for inclinedengaging means", each occurrence, read s incline engaging means Signed and sealed this 1st day of April 1958,

(SEAL) Attest:

KARL MINE ROBERT c. WATSON Attesting Officer Conmissioner of Patents 

